Factors controlling volatile organic compounds in dwellings in Melbourne,Australia

This study characterized indoor volatile organic compounds (VOCs) and investigated the effects of the dwelling characteristics, building materials, occupant activities, and environmental conditions on indoor VOC concentrations in 40 dwellings located in Melbourne, Australia, in 2008 and 2009. A total of 97 VOCs were identified. Nine VOCs, n‐butane, 2‐methylbutane, toluene, formaldehyde, acetaldehyde, d‐limonene, ethanol, 2‐propanol, and acetic acid, accounted for 68% of the sum of all VOCs. The median indoor concentrations of all VOCs were greater than those measured outdoors. The occupant density was positively associated with indoor VOC concentrations via occupant activities, including respiration and combustion. Terpenes were associated with the use of household cleaning and laundry products. A petroleum‐like indoor VOC signature of alkanes and aromatics was associated with the proximity of major roads. The indoor VOC concentrations were negatively correlated (P < 0.05) with ventilation. Levels of VOCs in these Australian dwellings were lower than those from previous studies in North America and Europe, probably due to a combination of an ongoing temporal decrease in indoor VOC concentrations and the leakier nature of Australian dwellings.     

Carcinoma of the male breast: a review and recommendations for management

OBJECTIVES: To investigate whether occupational exposure to organic solvents increases the risk of dementia. METHODS: Cases of dementia were identified from the computed tomography records of eight neuroradiology centres in England and Wales, and were compared with two sets of controls investigated at the same centres. The first set of controls were patients with brain cancer and the second set were patients with other disorders that were not chronically disabling. Lifetime occupational histories were obtained through a postal questionnaire completed by the subjects or their next of kin. Associations between dementia and occupation were examined by logistic regression. RESULTS: Usable questionnaires were returned for 204 (61%) of the cases, 225 (51%) of the controls with brain cancer, and 441 (61%) of the other controls. The findings with each of the two sets of controls were similar. In comparison with all controls combined, cases had less often worked ever as a painter or printer (odds ratio (OR) 0.6, 95% confidence interval (95% CI) 0.3 to 1.2), and were less likely to have worked for > 1 year as a printer, painter, or launderer or dry cleaner (OR 0.6, 95% CI 0.3 to 1.4). CONCLUSIONS: These findings provide no support for the hypothesis that occupational exposure to solvents is a cause of dementia. An excess risk in subsets of workers with extremes of exposure cannot be discounted, but the data indicate that any influence of exposure to solvents on the overall incidence of severe dementia in the general population of England and Wales is small.     

Distribution of HEOD (dieldrin) in mammals: III. Transport--transfer

A mathematical model simulating the blood transport and tissue residue distributions of the highly toxic and highly lipid soluble pesticide dieldrin in mammals is presented. This model is a significant improvement over our previously published preliminary model for dieldrin distribution in mammals. The assumptions and working hypotheses of the model are presented and used in generating a set of differential equations based upon mass balance principles. Two simulation cases are examined. The first simply demonstrates the gross features of: 1) Transport limiting conditions; 2) equal transport-equal membrane transfer conditions, and 3) membrane transfer limit conditions. The second studies a single tissue (the blood-brain barrier case) example of the above mentioned conditions. All simulations made were conducted for a hypothetical mature male rate of the average Wistar type eating food ad lib.     

The Winchester Graphics System: A Technical Overview

This paper gives a technical overview of the Winchester Graphics System. It concentrates on the software system, and in particular, the use of a relational database (PRTV). The main use of the system is in scientific research and it has been used a great deal in Chemistry, Biophysics and related sciences. However, the facilities are general and the same system is used for quite different applications. such as engineering and archaeology. This database has been found to provide researchers with a powerful flexible tool and has helped the UKSC to provide an environment where new ideas can be proposed and evaluated quickly and easily.     

Breast abscess due to Corynebacterium striatum

Corynebacterium striatum, a normal constituent of the skin flora, is rarely pathogenic. Previous reports of infection are few, and are mainly confined to immunosuppressed patients or those with indwelling prosthetic devices. We report a case in which the organism caused a recurrent breast abscess in a woman with normal immune function. The only previous reports of Corynebacterium striatum mastitis have been in cows.     

On binary tree encodements⋆

Summary A data encoding scheme involving binary tree encodements is presented and analyzed. A closed-form formula for the number of n-bit legal memory configurations is developed. It is shown that the storage capacity loss due to the use of this scheme is not significant for large n.This work was supported in part under the NCHSR Grant HS03792 and the NIH Grant R R00396     

Book Reviews

Book reviewed in this article: The Structure of Biopolymers . By Oswald Horer McGraw-Hill Book Co. Intracellular Staining in Neurobiology . Ed. by Stanley B. Kater and Charles Nicholson . Bacterial Membranes and Walls. Vol. I . Ed. by Loretta Lieve .     

High-accuracy differential image motion monitor measurements for the Thirty Meter Telescope site testing program

Differential image motion monitors (DIMMs) have become the industry standard for astronomical site characterization. The calibration of DIMMs is generally considered to be routine, but we show that particular care must be paid to this issue if high-accuracy measurements are to be achieved. In a side by side comparison of several DIMMs, we demonstrate that with proper care we can achieve an agreement between the seeing measurements of two DIMMS operating under the same conditions to better than +/-0.02 arc sec.     

Chemical Engineering Education in the Next Century

This paper summarizes the work of the EFCE Working Party Education (WPE) over the last decade and attempts to identify effective educational solutions to meet the challenges caused by the rapid rate of change in technology and society world‐wide. The paper uses the results of the 1994 WPE survey of curricula in European Chemical Engineering Universities to identify a first degree level core curriculum. The problem of how to adapt the discipline to meet technological and societal changes without losing its identity is addressed. Basic sciences, chemical engineering science, integrated systems design and holistic thinking are emphasized as essential elements of the discipline. The paper discusses how Safety, Health and Environment (SHE), biotechnology, computerized models, product design, sustainability and other new subjects have been incorporated into chemical engineering curricula since the original survey. A simple model of the education process is presented to indicate how students might obtain a chemical engineering understanding and mindset. The paper explains how chemical engineering evolved from its origins in the petrochemical, heavy chemical and nuclear industries, to its current wide range of applications in industries, such as fine chemicals, food, pharmaceuticals, software, and cybernetics. It is suggested that the impact of changes arising from industry, new technology and society has driven the chemical engineering discipline to a point where it is now ripe for re‐invention. The effects of rapid industrial, technological and societal change on chemical engineering education are studied against the backdrop of a discipline on the threshold of a significant change. The paper concludes by identifying curriculum development, personal development and life‐long learning as three important factors for educating chemical engineers for a successful future.